[plt-scheme] inheritance of private fields?

From: tom sgouros (tomfool at as220.org)
Date: Fri Feb 29 17:46:36 EST 2008

Matthias Felleisen <matthias at ccs.neu.edu> wrote:

> 
> On Feb 29, 2008, at 5:31 PM, tom sgouros wrote:
> 
> > This makes sense, and I maybe see what you're driving at with it.
> > Is it
> > correct to say that I should forget about what I was trying to do
> > (inherit the name and change the value) and just hide the data value I
> > have behind some accessor function and inherit that, as you do here?
> 
> 
> The field plus inherit-field parts were the essence. The accessor
> functions are a bad teaching ingredient. Sorry, I should do better.

But the field plus inherit-field is the easy part.  What I can't seem to
do is to change the value of that field in the daughter class.  I wanted
a class that had essentially a default value for a bunch of parameters,
and sub-classes would override some of those fields, and leave others
alone.

Perhaps I'm not thinking of this right.  I thought the fields were
variables I could address.  Perhaps I should think of them as constants?
Like "final" in Java?

> When you define something, it's hidden for good -- Matthias

Ok, that's clear.

Thanks,

 -tom


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